shouldEstablishInlineFormattingContext method

Implementation

bool shouldEstablishInlineFormattingContext() {
  // Block and inline-block containers can establish inline formatting contexts
  if (effectiveDisplay != CSSDisplay.block && effectiveDisplay != CSSDisplay.inlineBlock) {
    return false;
  }

  // Per CSS Inline Layout (css-inline-3) and CSS 2.1 §9.4.2, a block container
  // establishes an inline formatting context for its inline-level content
  // regardless of the 'overflow' property. Overflow only affects painting and
  // scrollability (block formatting context establishment), not whether inline
  // content forms line boxes. Therefore, do NOT early-return here when overflow
  // is not visible; allow IFC when the content qualifies.

  // Do not special-case BODY/HTML here. They can also establish IFC
  // when they contain only inline content and no block-level content.

  // Positioned elements (absolute/fixed) are taken out of normal flow with
  // respect to their placement, but their in-flow descendants still form
  // formatting contexts as usual. Per CSS 2.1 §9.4.1 and css-position-3,
  // an absolutely positioned block container with inline-level content
  // still establishes an inline formatting context for its content.
  // Therefore, do NOT block IFC establishment solely due to positioning.

  // Flex items may establish their own IFC; do not block based on parent.

  // Do not suppress IFC solely because the parent is inline-level.
  // A block container inside an inline element creates anonymous block boxes
  // and still establishes an inline formatting context for its inline content
  // per CSS 2.1 §9.2.1.1 and §9.4.2.

  // Check children from RenderObject perspective
  // This properly accounts for anonymous blocks
  return _shouldEstablishIFCFromRenderObject();
}